這邊需自行處理訊息，所以要加入兩個訊息
ON_NOTIFY_EX_RANGE(TTN_NEEDTEXTW, 0, 0xFFFF, OnToolTipText)
ON_NOTIFY_EX_RANGE(TTN_NEEDTEXTA, 0, 0xFFFF, OnToolTipText)
然後也需要改寫CListCtrl::OnToolHitTest()，裡面是用來設定UID，用途目前不明，但缺少的話，tip會閃一下就消失了。
int CXListCtrl::OnToolHitTest(CPoint point, TOOLINFO * pTI) const
{
//See if the point falls onto a list item
//UINT nFlags = 0;
LVHITTESTINFO lvhitTestInfo;
lvhitTestInfo.pt = point;
int nItem = ListView_SubItemHitTest(
this->m_hWnd,
&lvhitTestInfo);
int nSubItem = lvhitTestInfo.iSubItem;
UINT nFlags = lvhitTestInfo.flags;
//nFlags is 0 if the SubItemHitTest fails
//Therefore, 0 & <anything> will equal false
if (nFlags & m_wHistMask){
//If it did fall on a list item,
//and it was also hit one of the
//item specific sub-areas we wish to show tool tips for
//Get the client (area occupied by this control
RECT rcClient;
GetClientRect( &rcClient );
//Fill in the TOOLINFO structure
pTI->hwnd = m_hWnd;
pTI->uId = (UINT) (nItem * 100 + nSubItem);
pTI->lpszText = LPSTR_TEXTCALLBACK;
pTI->rect = rcClient;
return pTI->uId; //By returning a unique value per listItem,
//we ensure that when the mouse moves over another list item,
//the tooltip will change
}else{
//Otherwise, we aren't interested, so let the message propagate
return -1;
}
}
再來就是上面自己定義的Function，tip所要顯示的文字就在這這裡面設定：
BOOL CXListCtrl::OnToolTipText(UINT id, NMHDR* pNMHDR, LRESULT* pResult)
{
//Handle both ANSI and UNICODE versions of the message
TOOLTIPTEXTA* pTTTA = (TOOLTIPTEXTA*)pNMHDR;
TOOLTIPTEXTW* pTTTW = (TOOLTIPTEXTW*)pNMHDR;
//Ignore messages from the built in tooltip, we are processing them internally
if( (pNMHDR->idFrom == (UINT)m_hWnd) &&
( ((pNMHDR->code == TTN_NEEDTEXTA) && (pTTTA->uFlags &
TTF_IDISHWND)) ||
((pNMHDR->code == TTN_NEEDTEXTW) && (pTTTW->uFlags & TTF_IDISHWND)) ) ){
return FALSE;
}
*pResult = 0;
CString strTipText;
//Get the mouse position
const MSG* pMessage;
pMessage = GetCurrentMessage();
ASSERT ( pMessage );
CPoint pt;
pt = pMessage->pt; //Get the point from the message
ScreenToClient( &pt ); //Convert the point's coords to be relative to this control
//See if the point falls onto a list item
LVHITTESTINFO lvhitTestInfo;
lvhitTestInfo.pt = pt;
int nItem = SubItemHitTest(&lvhitTestInfo);
int nSubItem = lvhitTestInfo.iSubItem;
UINT nFlags = lvhitTestInfo.flags;
//nFlags is 0 if the SubItemHitTest fails
//Therefore, 0 & <anything> will equal false
if( nFlags & m_wHistMask ){
//If it did fall on a list item,
//and it was also hit one of the
//item specific sub-areas we wish to show tool tips for
//Lookup the list item's text in the ToolTip Map
CString strKey;
strKey.Format(_T("%d"), nItem * 100 + nSubItem);
if( m_ToolTipMap.Lookup(strKey, strTipText ) ){
//If there was a CString associated with the list item,
//copy it's text (up to 80 characters worth, limitation of the TOOLTIPTEXT structure)
//into the TOOLTIPTEXT structure's szText member
//Deal with UNICODE
#ifndef _UNICODE
if (pNMHDR->code == TTN_NEEDTEXTA)
//lstrcpyn(pTTTA->szText, strTipText, 80);
lstrcpyn(pTTTA->szText, "AAA", 80);
else
//_mbstowcsz(pTTTW->szText, strTipText, 80);
_mbstowcsz(pTTTW->szText, "Double Click Me", 80);
#else
if (pNMHDR->code == TTN_NEEDTEXTA)
_wcstombsz(pTTTA->szText, strTipText, 80);
else
lstrcpyn(pTTTW->szText, strTipText, 80);
#endif
return FALSE; //We found a tool tip,
//tell the framework this message has been handled
////////////////////////////////////////////////////////////////////////////////
// ****** Special note *****
//
// Still don't understand why the function must return FALSE for CListCtrl
// so as not to cause flickering, as opposed to Nate Maynard's derivation
// from CTreeCtrl.
// I have experimented with disabling Tooltips for the control
// and found out that a "ghost" tooltip appears for a fraction of a second...
//
// I am completely at a loss...
// Seems to work, though...
//
////////////////////////////////////////////////////////////////////////////////
}
}
return FALSE; //We didn't handle the message,
}
Reference:Handling TTN_NEEDTEXT Notification for Tool Tips
